Air bearing at opposite side of linear tape to support tape into contact with head slider

ABSTRACT

A tape head and bearing assembly comprises an air bearing structure having a tape bearing surface with a plurality of openings therein configured to provide a continuous air bearing of pressurized air to support a linear tape moving along a path, the air bearing being provided on only one side of the linear tape. A head slider assembly, such as an HDD-type assembly, is positioned at the opposite side of the linear tape from the tape bearing surface and is configured to be in contact with the linear tape.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a continuation of parent application Ser. No.11/843,990, filed Aug. 23, 2007, now U.S. Pat. No. 7,869,163.

FIELD OF THE INVENTION

This invention relates to tape, for example tape that may be employedfor magnetic recording, and, more particularly, to the interface betweenthe tape and a tape head.

BACKGROUND OF THE INVENTION

Tape, for example magnetic linear tape, may provide a means of recordingdata to be saved and read back at a subsequent time. The elements of thehead to conduct the recording and read back of the data may sharetechnologies with those of HDDs (Hard Disk Drives), but the highervolume of HDDs is accompanied by an economy of scale that may be used toadvantage with magnetic linear tape. HDDs and linear tape differ intechnology at the interface with respect to the head. An HDD is designedto position a head in proximity to a rigid substrate in which the headat least theoretically flies at a controlled flying height above thesurface.

Linear tape is instead a flexible substrate, and the typical tape headis rigid. The flexible tape is moved along a linear tape path andacross, and at least theoretically in contact with, the rigid head.

SUMMARY OF THE INVENTION

Tape head assemblies, tape drive assemblies, tape-head interfaceapparatus and methods are provided for supporting linear tape in contactwith tape heads.

In one embodiment, a tape head and bearing assembly comprises an airbearing structure having a tape bearing surface with a plurality ofopenings therein configured to provide a continuous air bearing ofpressurized air to support linear tape moving along a path, the airbearing provided on only one side of the tape; and a head sliderassembly positioned on the side of the linear tape opposite from thetape bearing surface, the assembly configured to be in contact with thelinear tape.

In a further embodiment, the elongated tape bearing surface comprises aconvex curved cylindrical surface elongated in the linear direction ofthe path.

In another embodiment, the head slider assembly comprises an HDD-typeassembly supported by a suspension arm assembly and configured to be incontact with the linear tape.

In a further embodiment, the air bearing structure additionallycomprises an air plenum wherein the plurality of openings are configuredto provide paths for pressurized air between the air plenum and the tapebearing surface.

In a still further embodiment, a source of pressurized air is configuredto supply the pressurized air to the air plenum.

In another embodiment, a tape-head interface apparatus comprises an airbearing structure comprising a tape bearing surface with a plurality ofopenings therein and an air plenum, wherein the plurality of openingsare configured to provide paths for pressurized air between the airplenum and the tape bearing surface, the air bearing configured toprovide an air bearing of pressurized air to support linear tape movingalong a path, the air bearing provided on only one side of the lineartape; a source of pressurized air configured to supply the pressurizedair to the air plenum; a head slider assembly positioned at the side ofthe linear tape opposite from the tape bearing surface and configured tobe in contact with the linear tape; and a drive spindle configured tomove the linear tape along the path, the path arranged in a continuousclosed loop encompassing the tape bearing surface and the drive spindle.

For a fuller understanding of the present invention, reference should bemade to the following detailed description taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic illustration of a tape and head interfaceassembly in accordance with the present invention;

FIG. 2 is a diagrammatic illustration of a tape drive assembly employingthe tape and head interface assembly of FIG. 1;

FIG. 3 is a cut away view of the air plenum and air bearing surface ofthe tape and head interface assembly of FIG. 1;

FIG. 4 is side view of a head slider assembly of the tape and headinterface of FIG. 1;

FIG. 5 is an isometric diagrammatic illustration of the head sliderassembly of FIG. 4;

FIG. 6 is an isometric diagrammatic illustration of the head slider ofthe head slider assembly of FIG. 5;

FIG. 7 is an isometric view of the arm and head slider of the headslider assembly of FIG. 5; and

FIG. 8 is a flow chart depicting a method in accordance with the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

This invention is described in preferred embodiments in the followingdescription with reference to the Figures, in which like numbersrepresent the same or similar elements. While this invention isdescribed in terms of the best mode for achieving this invention'sobjectives, it will be appreciated by those skilled in the art thatvariations may be accomplished in view of these teachings withoutdeviating from the spirit or scope of the invention.

Referring to FIGS. 1 and 2, a tape-head interface 100 of a tape driveassembly 110 is illustrated employing an air bearing structure 115having a tape bearing surface 120 configured to provide a continuous airbearing of pressurized air to support a linear tape 130 moving along apath 135, the air bearing provided on only one side of the linear tape.

A drive spindle 140 is configured to move the linear tape 130 along thepath 135. For example, the spindle 140 rotates in the clockwisedirection 142 to move the linear tape 130 in a continuous closed loop inthe direction of arrow 145, the closed loop encompassing the tapebearing surface 120 and the drive spindle 140. Additional air bearings150 may be placed along the linear tape path 135, and one or more idlerollers 152 may be employed to control the tension of the linear tape.Alternatively, a drive may be employed to move the linear tape between asupply reel and a take-up reel. A source of pressurized air 155, such asan air pump, provides pressurized air to each of the air bearings 115,150.

Referring additionally to FIG. 3, the air bearing structure 115comprises a tape bearing surface 120 with a plurality of openings 160therein configured to provide an air bearing of pressurized air tosupport a linear tape. The air bearing structure additionally comprisesan air plenum 165, which may comprise one or more compartments, suppliedby the source of pressurized air 155, and the plurality of openings 160are configured to provide paths for pressurized air between the airplenum 165 and the tape bearing surface 120.

The tape bearing surface 120 may be arranged in a convex curvedcylindrical surface elongated in the linear direction of the linear tapepath 135. The term “convex curved cylindrical surface” encompasses aperfect cylindrical surface, an annular cylindrical surface, or acylindrical surface having a variable radius.

Referring additionally to FIGS. 4, 5, 6, and 7, a head slider assembly240 mounted on a suspension arm assembly 220 is positioned at theopposite side of the linear tape 130 from the tape bearing surface 120.(FIGS. 5 and 6 illustrate the head slider assembly 240 from theviewpoint of the linear tape 130.) The air bearing 210 of pressurizedair at the tape bearing surface 120 supports the linear tape 130 on onlyone side of the tape and into contact with the head slider assembly 240.The suspension arm assembly may comprise a gimbal 222 that allows thehead slider assembly to pivot about both the “X” axis 230 and the “Y”axis 232 to follow the linear tape 130 as it may vary in position orattitude as it is moved in direction 145.

The head slider assembly may comprise an HDD-type assembly with a head250 configured for reading and writing information with respect to amagnetic media. The head may also comprise a plurality of rails 260 forsupporting the head slider assembly in contact with the linear tape 130,for example, forming an area of support with the head 250 to maintainstability of the HDD-type assembly. In one arrangement of HDD-typeassemblies, the rails form a negative pressure area around the head 250to draw the head into contact with the linear tape, requiring lesspressure from the suspension arm assembly 220. Alternative arrangementsof the rails and the head 250 may be provided by HDD-type assembliesincluding those not having a negative pressure area. Cabling 270 may beconfigured to provide communication with the head 250 for reading andwriting information with respect to the magnetic linear tape.

Referring additionally to FIG. 8, in step 300, the air bearing structure115 having a tape bearing surface 120 with a plurality of openings 160therein is configured to provide a continuous air bearing 210 ofpressurized air to support a linear tape moving along a path, the airbearing on only one side of the linear tape; and, in step 310, the headslider assembly 240 is positioned at the side of the linear tape 130opposite from the tape bearing surface 120. In step 320, the linear tape130 is placed between the tape bearing surface 120 of the air bearingstructure 115 and the head slider assembly 240, and the air bearing 210is generated by the source of pressurized air 155 via openings 160 inthe tape bearing surface to place the linear tape in contact with thelinear tape 130. In step 330, spindle 140 moves the linear tape alongthe tape path 135.

The linear tape 130 may comprise magnetic tape and the head sliderassembly 240 may be employed to read and write information with respectto the magnetic tape, thereby storing information on the magnetic tapefor subsequent retrieval. Alternatively, the linear tape may comprise aclear tape, and interferometry apparatus may be employed to evaluate thehead-tape interface. Still alternatively, the linear tape may bearranged in other than a closed loop, for example with a drive to movethe linear tape between a supply reel and a take-up reel.

An example of a best mode application employed for tape characterizationor tape-head interface characterization comprises an air bearingstructure having a curved cylindrical surface fabricated out of aceramic, such as silicon carbide, or a metal, such as aluminium. The airplenum structure is machined into an area close to the surface, andholes of 250 microns uniformly spaced by 2 mm are drilled to provide airflow from the plenum to the surface. An air supply pressure of 5-20 psican be supplied to the plenum. The curved cylindrical surface comprisesa 60.5 mm radius and 12.7 mm width. The tape is held in a closed loopand driven by a 90 mm diameter drive spindle.

The above discussion is not intended to restrict alternative modes orexamples of implementation of the present invention, such as thosediscussed supra.

Those of skill in the art will understand that changes may be made withrespect to the embodiments illustrated herein. Further, those of skillin the art will understand that differing specific componentarrangements may be employed than those illustrated herein.

While the preferred embodiments of the present invention have beenillustrated in detail, it should be apparent that modifications andadaptations to those embodiments may occur to one skilled in the artwithout departing from the scope of the present invention as set forthin the following claims.

1. A tape head and bearing assembly comprising: an air bearing structurehaving a tape bearing surface with a plurality of openings thereinconfigured to provide a continuous air bearing of pressurized air tosupport a linear tape moving along a path, said air bearing beingprovided on only one side of said linear tape; and a head sliderassembly positioned at the side of said linear tape opposite from saidtape bearing surface, said assembly configured to be in contact withsaid linear tape directly opposite said air bearing such that said airbearing supports said linear tape into contact with said head sliderassembly.
 2. The tape head and bearing assembly of claim 1, wherein saidtape bearing surface comprises a convex curved cylindrical surfaceelongated in the linear direction of said path.
 3. The tape head andbearing assembly of claim 2, wherein said head slider assembly comprisesan HDD-type assembly supported by a suspension arm assembly andconfigured to be in said contact with said linear tape.
 4. The tape headand bearing assembly of claim 3, wherein said air bearing structureadditionally comprises an air plenum; and wherein said plurality ofopenings are configured to provide paths for pressurized air betweensaid air plenum and said tape bearing surface.
 5. The tape head andbearing assembly of claim 4, additionally comprising a source ofpressurized air configured to supply said pressurized air to said airplenum.
 6. A tape drive assembly comprising: an air bearing structurehaving a tape bearing surface with a plurality of openings thereinconfigured to provide a continuous air bearing of pressurized air tosupport linear tape moving along a path, said air bearing being providedon only one side of said linear tape; a head slider assembly positionedat the side of said linear tape opposite from said tape bearing surface,said assembly configured to be in contact with said linear tape directlyopposite said air bearing such that said air bearing supports saidlinear tape into contact with said head slider assembly; and a drivespindle configured to move said linear tape along said path.
 7. The tapedrive assembly of claim 6, wherein said tape bearing surface comprises aconvex curved cylindrical surface elongated in the linear direction ofsaid linear tape path.
 8. The tape drive assembly of claim 7, whereinsaid head slider assembly comprises an HDD-type assembly supported by asuspension arm assembly and configured to be in said contact with saidlinear tape.
 9. The tape drive assembly of claim 8, wherein said airbearing structure additionally comprises an air plenum; and wherein saidplurality of openings are configured to provide paths for pressurizedair between said air plenum and said tape bearing surface.
 10. The tapedrive assembly of claim 9, additionally comprising a source ofpressurized air configured to supply said pressurized air to said airplenum.
 11. The tape drive assembly of claim 6, additionally comprisingsaid linear tape arranged in a continuous closed loop.
 12. Tape-headinterface apparatus comprising: an air bearing structure comprising atape bearing surface with a plurality of openings therein and an airplenum, wherein said plurality of openings are configured to providepaths for pressurized air between said air plenum and said tape bearingsurface, said air bearing structure configured to provide a continuousair bearing of pressurized air to support linear tape moving along apath, said air bearing on only one side of said linear tape; a source ofpressurized air configured to supply said pressurized air to said airplenum; a head slider assembly positioned at the side of said lineartape opposite from said tape bearing surface, said assembly configuredto be in contact with said linear tape; and a drive spindle configuredto move said linear tape along said path, said path arranged in acontinuous closed loop encompassing said tape bearing surface and saiddrive spindle.
 13. The tape-head interface apparatus of claim 12,additionally comprising said linear tape arranged in said continuousclosed loop and wherein said head slider assembly comprises an HDD-typeassembly supported by a suspension arm assembly.
 14. A method forpositioning a head slider assembly in proximal contact with a lineartape comprising the steps of: providing a single air bearing along oneside only of a tape path; and positioning said head slider assembly atsaid tape path opposite said single air bearing, such that placement ofsaid linear tape between said single air bearing and said head sliderassembly allows said single air bearing to support said linear tape onone side only, said single air bearing contacting said linear tapedirectly opposite said head slider assembly to support said linear tapeinto contact with said head slider assembly.
 15. The method of claim 14,wherein said step of providing said single elongated air bearingcomprises forming said single air bearing over a tape bearing surfacehaving a plurality of openings therein.
 16. A tape-head interfaceapparatus comprising: a head slider assembly; and a single air bearingstructure positioned opposite said head slider assembly configured toprovide a continuous air bearing of pressurized air; wherein a lineartape positioned between said head slider assembly and said single airbearing structure has only one surface that rides over said pressurizedair bearing directly opposite said head slider assembly such that saidair bearing supports said linear tape in contact with said head sliderassembly.
 17. The tape-head interface apparatus of claim 16, whereinsaid head slider assembly comprises an HDD-type assembly supported by asuspension arm assembly and configured to be in said contact with saidlinear tape.
 18. The tape-head interface apparatus of claim 17, whereinsaid air bearing structure additionally comprises an air plenum, an airbearing surface, and a plurality of openings configured to provide pathsfor pressurized air between said air plenum and said air bearing surfaceto form said air bearing.
 19. The tape-head interface apparatus of claim18, additionally comprising a source of pressurized air configured tosupply said pressurized air to said air plenum.